Chairs

ABSTRACT

1,124,241. Adjustable seats. TAN-SAD CHAIR CO. (1931) Ltd. 27 Jan., 1966 [13 Feb., 1965], No. 6342/65. Heading A4J. Bolt 17 retains back rest 4, of an office chair, in its adjusted position and can be unscrewed to allow the rest to be altered in height and inclination. Spring 23 separates serrations 8 from those on a complementary cylindrical surface 12, thus allowing bolt 17 and the assembly 4, 5, 6 and 15 to be swung about the axis of cylindrical nut 20, which is journalled in seat frame 3. Slot 19 allows stem 5 to be slid vertically. U-shaped clamping. member 15 grips stem 5, on re-tightening bolt 17.

Nov. 7, 1967 1 .J. STREET 3,351,379

CHAIRS Filed Feb. 1. 1966 FIG.2

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s I I! I gig-U z 2 L l 25 eu-rag LESLIE J'oHA/ STRE ET United StatesPatent 3,351,379 CHAIRS Leslie John Street, Bristol, England, assignorto The Tan- Sad Chair (Iompany (1931) Limited, Birmingham, England, aBritish company Filed Feb. 1, 1966, Ser. No. 534,939 Claims priority,application Great Britain, Feb. 13, 1965, 6,342/ 65 10 Claims. (Cl.297-358) ABSTRACT OF THE DISCLUSURE An adjustable chair comprises aback-rest assembly and a seat assembly. A block, in which the uprightstern of the back-rest assembly is vertically slidably mounted, isangularly adjustable about a horizontal axis on the seat assembly, therebeing cooperating serrated locking surfaces on the block and seatassembly. Adjustment of the stern relative to the block and the blockrelative to the seat assembly is controlled by a common bolt thatextends rotatably through the block and a vertically elongated slot inthe stem to a combined pivotal and threaded connection with the seatassembly. A U-shaped clamping member disposed between the bolt head andthe block laterally encloses the block and stem.

This invention relates to chairs of the kind commonly known as typistschairs and comprising separate seat and back-rest assemblies.

The invention has for its object the provision in a typists chair ofimproved means for adjusting both the angular and height relationshipbetween the seat and back-rest assemblies which means is of particularlysimple construction, is cheap to manufacture, and is easily operated andmaintained by the user.

In accordance with the invention a typists chair comprises seat andback-rest assemblies secured together through adjusting means includinga block, complementary surfaces (preferably having complementaryserrations) on the block and seat assembly capable of selectiveengagement to determine the angular position of the block in relation tothe seat assembly about a horizontal axis, a dependant stem of the seatassembly abutting the block, and a bolt passing through a verticallyelongated slot in the stem and through the block in a directionperpendicular to the complementary surfaces to have screw engagementwith the seat assembly, the rotation of the bolt serving simultaneouslyto clamp the block in its selected angular position and to clamp thestem against said block at a selected height both in relation to theseat assembly.

A typical example of the practical realisation of the invention isillustrated in the accompanying drawings, wherein:

FIGURE 1 is a part-sectional side elevation showing the parts of atypists chair relevant to the invention, and

FIGURE 2 is a fragmentary and part-sectional plan View of certain of theparts of FIGURE 1 on an enlarged scale.

Referring to the drawings, a typists chair comprises a seat assemblyincluding a die cast seat frame 3 adapted to surmount a pedestal and tocarry a seat pad (both not shown) and a back-rest assembly including apad 4 mounted on the head of a stem 5 of rectangular crosssectionadapted for attachment to the seat frame 3 via an adjusting means.

The adjusting means comprises a block 6 having a flat rear face 7 andhorizontally extending serrations 8 in a cylindrically concave frontface protruding forwardly beyond a pair of cylindrically concavemarginal portions 9. The block 6 has a bore 10 extending along a radiusfrom Patented Nov. 7, 1967 the horizontal axis of curvature O of thecylindrically concave faces 8 and 9.

An integral rear portion 11 of the frame 3 is provided with inner andouter cylindrically convex regions 12 and 13 complementary to theconcave faces 8 and 9 of the block, and the inner convex face 12 hasserrations complementary to those of the block face 8. The serratedportion 12 of the seat frame embodies a vertically elongated slot 14.

The adjusting means further comprises a clamping member 15 of U-shape inhorizontal cross-section having side flanges 25 shaped to overlapportions of the sides of the stem 5, the sides of the block 6, andmarginal parts of the seat frame portion 11, thereby to conceal themajor part of the block. The clamping member is formed with a centralbore 16.

The adjusting means is completed by a bolt 17 which extends from anintegral hand piece 18, forming the head of the bolt through the closefitting bore 16 in the clamping member, through a vertically elongatedslot 19 in the stem 5, through the close fitting bore 10 in the block 6,and through the elongated slot 14 in the seat frame 3 to have screwengagement with an element in the form of a cylindrical cross-bar 20journalled at the axis of curvature O of the serrated portions 8 and 12and between a pair of flanges 21 integral with the seat frame. A pin orcirclip 22 may be mounted in or about the bolt 17 to prevent accidentalwithdrawal of the bolt from the crossbar 2%).

In use, to adjust both the angle and height of the backrest assembly inrelation to the seat frame assembly the hand piece 18 is manuallyrotated sufliciently to allow disengagement of the complementaryserrated parts 8 and 12 and so permit angular movement together of theblock 6, stem 5, clamping member 15, bolt 17 and cross bar 20 inrelation to the seat frame 3 about the horizontal axis 0 within thelimits determined by the available movement of the bolt 17 within theseat frame slot 14. Simultaneously the height of the back-rest stem 5 isadjusted by its sliding between the clamping member 15 and block 6.After selection of both the angle and height of the back-rest assemblythe hand piece 18 is rotated in a direction to tighten the parts and tore-engage the complementary serrations 8 and 12 so as to lock theadjusting means in selected position.

Optionally a compression spring 23 can be mounted about the bolt 17 toabut between the cross-bar 20 and block 6 so as to bias the latter awayfrom the seat frame 3 and so facilitate slackening of the parts.

Compared with previously known means for adjusting both the relativeangles and heights of seat and back rest assemblies, that according tothe invention is particularly simple, compact and positive in operationand requires no adjustment in use to take up the effects of wear otherthan that automatically alforded by the bolt 17 in its normal clampingfunction.

I claim:

1. A chair for typists and the like comprising seat and back-restassemblies secured together through adjusting means including a block,complementary surfaces on the block and seat assembly capable ofselective locked engagement to determine the angular position of theblock about a horizontal axis, a dependant stem of the seat assemblyslidably connected to the block, a bolt passing through a verticallyelongated slot in the stem and through the block in a directionsubstantially perpendicular to the complementary surfaces, and coactingmeans on said bolt and said seat assembly providing a combined pivotaland threaded connection therebetween whereby rotation of said bolt inone direction enables said complementary surfaces to be released andpermits said block and bolt to swing together about said connectionangularly relative to the seat assembly, and rotation of the bolt in theopposite direction serves simultaneously to clamp the block to the seatassembly in the selected angular position and to clamp the stem againstthe block at a selected height in relation to the seat assembly.

2. A chair according to claim 1 wherein the complementary surfaces havecomplementary serrations disposed on arcs substantially concentric withthe pivot axis at said connection.

3. A chair according to claim 2 wherein said connec- 7 tion comprises apivot element pivotally mounted about a generally horizontal axis in theseat assembly and having a threaded cross bore for screw engagement withthe bolt.

4. A chair according to claim 3, wherein said pivot element is rotatablymounted in and between a spaced pair of flanges integral with a frame ofthe seat assembly.

5. A chair according to claim 1 comprising a clamping member disposedbetween a head of the bolt and the stem whereby when the bolt is rotatedin said opposite direction the stem is clamped between the clampingmember and said block.

6. A chair according to claim 5, wherein the head of the bolt takes theform of a manually rotatable hand piece.

7. A chair according to claim 5, wherein the bolt passes rotatablythrough close fitting apertures in the clamping member and block andthrough a vertically elongated gap in the seat assembly to permitrocking together of the clamping member, block, pivot element and boltabout the axis of said connection during adjustment.

8. A chair according to claim 5, wherein the clamping member is ofU-shape in horizontal cross-section with side flanges overlying thesides of the stem and block.

9. A chair according to claim 2, wherein the block and seat assemblycomprise second complementary and cylindrically curved surfaces coaxialwith and horizontally spaced from the surfaces incorporating theserrations.

10. A chair according to claim 1 wherein spring means is compressedbetween the block and the seat assembly for urging said complementarysurfaces apart When said bolt is rotated in said one direction.

References Cited UNITED STATES PATENTS 1,277,726 9/1918 Hunn 2973581,696,153 12/1928 Bump 297-358 1,860,096 5/1932 Headley 297-3582,137,335 11/1938 Gabb 297-358 2,421,702 6/1947 Jones 297358 2,590,7183/1952 Lundquist 297375 X 2,845,994 8/1958 Thompson 297357 X DAVID J.WILLIAMOWSKY, Primary Examiner.

G. O. FINCH, Assistant Examiner.

1. A CHAIR FOR TYPISTS AND THE LIKE COMPRISING SEAT AND BACK-RESTASSEMBLIES SECURED TOGETHER THROUGH ADJUSTING MEANS INCLUDING A BLOCK,COMPLEMENTARY SURFACES ON THE BLOCK AND SEAT ASSEMBLY CAPABLE OFSELECTIVE LOCKED ENGAGEMENT TO DETERMINE THE ANGULAR POSITION OF THEBLOCK ABOUT A HORIZONTAL AXIS, A DEPENDANT STEM OF THE SEAT ASSEMBLYSLIDABLY CONNECTED TO THE BLOCK, A BOLT PASSING THROUGH A VERTICALLYELONGATED SLOT IN THE STEM AND THROUGH THE BLOCK IN A DIRECTIONSUBSTANTIALLY PERPENDICULAR TO THE COMPLEMENTARY SURFACES, AND COACTINGMEANS ON SAID BOLT AND SAID SEAT ASSEMBLY PROVIDING A COMBINED PIVOTALAND THREADED CONNECTION THEREBETWEEN WHEREBY ROTATION OF SAID BOLT INONE DIRECTION ENABLES SAID COMPLEMENTARY SURFACES TO BE RELEASED ANDPERMITS SAID BLOCK AND BOLT TO SWING TOGETHER ABOUT SAID CONNECTIONANGULARLY RELATIVE TO THE SEAT ASSEMBLY, AND ROTATION OF THE BOLT IN THEOPPOSITE DIRECTION SERVES SIMULTANEOUSLY TO CLAMP THE BLOCK TO THE SEATASSEMBLY IN THE SELECTED ANGULAR POSITION AND TO CLAMP THE STEM AGAINSTTHE BLOCK AT A SELECTED HEIGHT IN RELATION TO THE SEAT ASSEMBLY.